The path of pre-ribosomes through the nuclear pore complex revealed by electron tomography

Nat Commun. 2019 Jan 30;10(1):497. doi: 10.1038/s41467-019-08342-7.

Abstract

Determining the path of single ribonucleoprotein (RNP) particles through the 100 nm-wide nuclear pore complex (NPC) by fluorescence microscopy remains challenging due to resolution limitation and RNP labeling constraints. By using high-pressure freezing and electron tomography, here we captured snapshots of the translocation of native RNP particles through NPCs in yeast and analyzed their trajectory at nanometer-scale resolution. Morphological and functional analyses indicate that these particles mostly correspond to pre-ribosomes. They are detected in 5-6% of the NPCs, with no apparent bias for NPCs adjacent to the nucleolus. Their path closely follows the central axis of the NPC through the nuclear and inner rings, but diverges at the cytoplasmic ring, suggesting interactions with the cytoplasmic nucleoporins. By applying a probabilistic queueing model to our data, we estimated that the dwell time of pre-ribosomes in the yeast NPC is ~90 ms. These data reveal distinct steps of pre-ribosome translocation through the NPC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / metabolism
  • Cell Nucleus / ultrastructure
  • Cytoplasm / metabolism
  • Cytoplasm / ultrastructure
  • Electron Microscope Tomography*
  • Microscopy, Fluorescence
  • Nuclear Envelope / metabolism
  • Nuclear Envelope / ultrastructure
  • Nuclear Pore / metabolism*
  • Nuclear Pore / ultrastructure
  • Nuclear Pore Complex Proteins / metabolism
  • Nuclear Pore Complex Proteins / ultrastructure
  • Ribosomes / metabolism
  • Ribosomes / ultrastructure*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae / ultrastructure

Substances

  • Nuclear Pore Complex Proteins